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linux-7.2.3/arch/x86/entry/vdso/common/Makefile.include

@@ -0,0 +1,89 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Building vDSO images for x86.
+#
+
+# Include the generic Makefile to check the built vDSO:
+include $(srctree)/lib/vdso/Makefile.include
+
+obj-y    += $(foreach x,$(vdsos-y),vdso$(x)-image.o)
+
+targets  += $(foreach x,$(vdsos-y),vdso$(x)-image.c vdso$(x).so vdso$(x).so.dbg vdso$(x).lds)
+targets  += $(vobjs-y)
+
+# vobjs-y with $(obj)/ prepended
+vobjs := $(addprefix $(obj)/,$(vobjs-y))
+
+# Options for vdso*.lds
+CPPFLAGS_VDSO_LDS := -P -C -I$(src)/..
+$(obj)/%.lds : KBUILD_CPPFLAGS += $(CPPFLAGS_VDSO_LDS)
+
+#
+# Options from KBUILD_[AC]FLAGS that should *NOT* be kept
+#
+flags-remove-y += \
+	-D__KERNEL__ -mcmodel=kernel -mregparm=3 \
+	-fno-pic -fno-PIC -fno-pie -fno-PIE \
+	-mfentry -pg \
+	$(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(KSTACK_ERASE_CFLAGS) \
+	$(RETPOLINE_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \
+	$(PADDING_CFLAGS)
+
+#
+# Don't omit frame pointers for ease of userspace debugging, but do
+# optimize sibling calls.
+#
+flags-y += -D__DISABLE_EXPORTS
+flags-y += -DDISABLE_BRANCH_PROFILING
+flags-y += -DBUILD_VDSO
+flags-y += -I$(src)/.. -I$(srctree)
+flags-y += -O2 -fpic
+flags-y += -fno-stack-protector
+flags-y += -fno-omit-frame-pointer
+flags-y += -foptimize-sibling-calls
+flags-y += -fasynchronous-unwind-tables
+
+# Reset cf protections enabled by compiler default
+flags-y += $(call cc-option, -fcf-protection=none)
+flags-$(X86_USER_SHADOW_STACK) += $(call cc-option, -fcf-protection=return)
+# When user space IBT is supported, enable this.
+# flags-$(CONFIG_USER_IBT) += $(call cc-option, -fcf-protection=branch)
+
+flags-$(CONFIG_MITIGATION_RETPOLINE) += $(RETPOLINE_VDSO_CFLAGS)
+
+# These need to be conditional on $(vobjs) as they do not apply to
+# the output vdso*-image.o files which are standard kernel objects.
+$(vobjs) : KBUILD_AFLAGS := \
+	$(filter-out $(flags-remove-y),$(KBUILD_AFLAGS)) $(flags-y)
+$(vobjs) : KBUILD_CFLAGS := \
+	$(filter-out $(flags-remove-y),$(KBUILD_CFLAGS)) $(flags-y)
+
+#
+# The VDSO images are built using a special linker script.
+#
+VDSO_LDFLAGS := -shared --hash-style=both --build-id=sha1 --no-undefined \
+	$(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack
+
+quiet_cmd_vdso = VDSO    $@
+      cmd_vdso = $(LD) -o $@ \
+		       $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$*) \
+		       -T $(filter %.lds,$^) $(filter %.o,$^)
+quiet_cmd_vdso_and_check = VDSO    $@
+      cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
+
+$(obj)/vdso%.so.dbg: $(obj)/vdso%.lds FORCE
+	$(call if_changed,vdso_and_check)
+
+$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+	$(call if_changed,objcopy)
+
+VDSO2C = $(objtree)/arch/x86/tools/vdso2c
+
+quiet_cmd_vdso2c = VDSO2C  $@
+      cmd_vdso2c = $(VDSO2C) $< $(<:%.dbg=%) $@
+
+$(obj)/%-image.c: $(obj)/%.so.dbg $(obj)/%.so $(VDSO2C) FORCE
+	$(call if_changed,vdso2c)
+
+$(obj)/%-image.o: $(obj)/%-image.c

linux-7.2.3/arch/x86/entry/vdso/common/note.S

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#include <linux/build-salt.h>
+#include <linux/version.h>
+#include <linux/elfnote.h>
+
+/* Ideally this would use UTS_NAME, but using a quoted string here
+   doesn't work. Remember to change this when changing the
+   kernel's name. */
+ELFNOTE_START(Linux, 0, "a")
+	.long LINUX_VERSION_CODE
+ELFNOTE_END
+
+BUILD_SALT

linux-7.2.3/arch/x86/entry/vdso/common/vclock_gettime.c

@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Fast user context implementation of clock_gettime, gettimeofday, and time.
+ *
+ * Copyright 2006 Andi Kleen, SUSE Labs.
+ * Copyright 2019 ARM Limited
+ *
+ * 32 Bit compat layer by Stefani Seibold <stefani@seibold.net>
+ *  sponsored by Rohde & Schwarz GmbH & Co. KG Munich/Germany
+ */
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <vdso/gettime.h>
+
+#include "lib/vdso/gettimeofday.c"
+
+int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
+{
+	return __cvdso_gettimeofday(tv, tz);
+}
+
+int gettimeofday(struct __kernel_old_timeval *, struct timezone *)
+	__attribute__((weak, alias("__vdso_gettimeofday")));
+
+__kernel_old_time_t __vdso_time(__kernel_old_time_t *t)
+{
+	return __cvdso_time(t);
+}
+
+__kernel_old_time_t time(__kernel_old_time_t *t)	__attribute__((weak, alias("__vdso_time")));
+
+
+#if defined(CONFIG_X86_64) && !defined(BUILD_VDSO32_64)
+/* both 64-bit and x32 use these */
+int __vdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_gettime(clock, ts);
+}
+
+int clock_gettime(clockid_t, struct __kernel_timespec *)
+	__attribute__((weak, alias("__vdso_clock_gettime")));
+
+int __vdso_clock_getres(clockid_t clock,
+			struct __kernel_timespec *res)
+{
+	return __cvdso_clock_getres(clock, res);
+}
+int clock_getres(clockid_t, struct __kernel_timespec *)
+	__attribute__((weak, alias("__vdso_clock_getres")));
+
+#else
+/* i386 only */
+int __vdso_clock_gettime(clockid_t clock, struct old_timespec32 *ts)
+{
+	return __cvdso_clock_gettime32(clock, ts);
+}
+
+int clock_gettime(clockid_t, struct old_timespec32 *)
+	__attribute__((weak, alias("__vdso_clock_gettime")));
+
+int __vdso_clock_gettime64(clockid_t clock, struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_gettime(clock, ts);
+}
+
+int clock_gettime64(clockid_t, struct __kernel_timespec *)
+	__attribute__((weak, alias("__vdso_clock_gettime64")));
+
+int __vdso_clock_getres(clockid_t clock, struct old_timespec32 *res)
+{
+	return __cvdso_clock_getres_time32(clock, res);
+}
+
+int clock_getres(clockid_t, struct old_timespec32 *)
+	__attribute__((weak, alias("__vdso_clock_getres")));
+
+int __vdso_clock_getres_time64(clockid_t clock, struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_getres(clock, ts);
+}
+
+int clock_getres_time64(clockid_t, struct __kernel_timespec *)
+	__attribute__((weak, alias("__vdso_clock_getres_time64")));
+#endif

linux-7.2.3/arch/x86/entry/vdso/common/vdso-layout.lds.S

@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm/vdso.h>
+#include <asm/vdso/vsyscall.h>
+#include <vdso/datapage.h>
+
+/*
+ * Linker script for vDSO.  This is an ELF shared object prelinked to
+ * its virtual address, and with only one read-only segment.
+ * This script controls its layout.
+ */
+
+SECTIONS
+{
+	/*
+	 * User/kernel shared data is before the vDSO.  This may be a little
+	 * uglier than putting it after the vDSO, but it avoids issues with
+	 * non-allocatable things that dangle past the end of the PT_LOAD
+	 * segment.
+	 */
+
+	VDSO_VVAR_SYMS
+
+	vclock_pages = VDSO_VCLOCK_PAGES_START(vdso_u_data);
+	pvclock_page = vclock_pages + VDSO_PAGE_PVCLOCK_OFFSET * PAGE_SIZE;
+	hvclock_page = vclock_pages + VDSO_PAGE_HVCLOCK_OFFSET * PAGE_SIZE;
+
+	. = SIZEOF_HEADERS;
+
+	.hash		: { *(.hash) }			:text
+	.gnu.hash	: { *(.gnu.hash) }
+	.dynsym		: { *(.dynsym) }
+	.dynstr		: { *(.dynstr) }
+	.gnu.version	: { *(.gnu.version) }
+	.gnu.version_d	: { *(.gnu.version_d) }
+	.gnu.version_r	: { *(.gnu.version_r) }
+
+	.dynamic	: { *(.dynamic) }		:text	:dynamic
+
+	.rodata		: {
+		*(.rodata*)
+		*(.data*)
+		*(.sdata*)
+		*(.got.plt) *(.got)
+		*(.gnu.linkonce.d.*)
+		*(.bss*)
+		*(.dynbss*)
+		*(.gnu.linkonce.b.*)
+	}						:text
+
+	.note.gnu.property : {
+		*(.note.gnu.property)
+	}					:text :note :gnu_property
+	.note		: {
+		*(.note*)
+	}					:text :note
+
+	.eh_frame_hdr	: { *(.eh_frame_hdr) }	:text :eh_frame_hdr
+	.eh_frame	: {
+		KEEP (*(.eh_frame))
+		*(.eh_frame.*)
+	}					:text
+
+	/*
+	 * Text is well-separated from actual data: there's plenty of
+	 * stuff that isn't used at runtime in between.
+	 */
+
+	.text		: {
+		*(.text*)
+	}						:text	=0x90909090,
+
+
+
+	.altinstructions	: { *(.altinstructions) }	:text
+	.altinstr_replacement	: { *(.altinstr_replacement) }	:text
+
+	__ex_table		: { *(__ex_table) }		:text
+
+	/DISCARD/ : {
+		*(.discard)
+		*(.discard.*)
+		*(__bug_table)
+	}
+}
+
+/*
+ * Very old versions of ld do not recognize this name token; use the constant.
+ */
+#define PT_GNU_EH_FRAME	0x6474e550
+#define PT_GNU_STACK	0x6474e551
+#define PT_GNU_PROPERTY	0x6474e553
+
+/*
+ * We must supply the ELF program headers explicitly to get just one
+ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
+*/
+#define PF_R	FLAGS(4)
+#define PF_RW	FLAGS(6)
+#define PF_RX	FLAGS(5)
+
+PHDRS
+{
+	text		PT_LOAD		PF_RX FILEHDR PHDRS;
+	dynamic		PT_DYNAMIC	PF_R;
+	note		PT_NOTE		PF_R;
+	eh_frame_hdr	PT_GNU_EH_FRAME PF_R;
+	gnu_stack	PT_GNU_STACK	PF_RW;
+	gnu_property	PT_GNU_PROPERTY	PF_R;
+}

linux-7.2.3/arch/x86/entry/vdso/common/vfutex.c

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <vdso/futex.h>
+
+/*
+ * Assembly template for the try unlock functions. The basic functionality is:
+ *
+ *		mov		esi, %eax	Move the TID into EAX
+ *		xor		%ecx, %ecx	Clear ECX
+ *		lock_cmpxchgl	%ecx, (%rdi)	Attempt the TID -> 0 transition
+ * .Lcs_start:					Start of the critical section
+ *		jnz		.Lcs_end	If cmpxchl failed jump to the end
+ * .Lcs_success:				Start of the success section
+ *		movq		%rcx, (%rdx)	Set the pending op pointer to 0
+ * .Lcs_end:					End of the critical section
+ *
+ * .Lcs_start and .Lcs_end establish the critical section range. .Lcs_success is
+ * technically not required, but there for illustration, debugging and testing.
+ *
+ * When CONFIG_COMPAT is enabled then the 64-bit VDSO provides two functions.
+ * One for the regular 64-bit sized pending operation pointer and one for a
+ * 32-bit sized pointer to support gaming emulators.
+ *
+ * The 32-bit VDSO provides only the one for 32-bit sized pointers.
+ */
+#define __stringify_1(x...)	#x
+#define __stringify(x...)	__stringify_1(x)
+
+#define LABEL(prefix, which)	__stringify(prefix##_try_unlock_cs_##which:)
+
+#define JNZ_END(prefix)		"jnz " __stringify(prefix) "_try_unlock_cs_end\n"
+
+#define CLEAR_POPQ		"movq	%[zero],  %a[pop]\n"
+#define CLEAR_POPL		"movl	%k[zero], %a[pop]\n"
+
+#define futex_robust_try_unlock(prefix, clear_pop, __lock, __tid, __pop)\
+({									\
+	asm volatile (							\
+		"						\n"	\
+		"	lock cmpxchgl	%k[zero], %a[lock]	\n"	\
+		"						\n"	\
+		LABEL(prefix, start)					\
+		"						\n"	\
+		JNZ_END(prefix)						\
+		"						\n"	\
+		LABEL(prefix, success)					\
+		"						\n"	\
+			clear_pop					\
+		"						\n"	\
+		LABEL(prefix, end)					\
+		: [tid]   "+&a" (__tid)					\
+		: [lock]  "D"   (__lock),				\
+		  [pop]   "d"   (__pop),				\
+		  [zero]  "r"   (0UL)					\
+		: "memory"						\
+	);								\
+	__tid;								\
+})
+
+#ifdef __x86_64__
+__u32 __vdso_futex_robust_list64_try_unlock(__u32 *lock, __u32 tid, __u64 *pop)
+{
+	return futex_robust_try_unlock(__futex_list64, CLEAR_POPQ, lock, tid, pop);
+}
+#endif /* __x86_64__ */
+
+#if defined(CONFIG_X86_32) || defined(CONFIG_COMPAT)
+__u32 __vdso_futex_robust_list32_try_unlock(__u32 *lock, __u32 tid, __u32 *pop)
+{
+	return futex_robust_try_unlock(__futex_list32, CLEAR_POPL, lock, tid, pop);
+}
+#endif /* CONFIG_X86_32 || CONFIG_COMPAT */

linux-7.2.3/arch/x86/entry/vdso/common/vgetcpu.c

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2006 Andi Kleen, SUSE Labs.
+ *
+ * Fast user context implementation of getcpu()
+ */
+
+#include <linux/kernel.h>
+#include <asm/segment.h>
+#include <vdso/processor.h>
+
+notrace long
+__vdso_getcpu(unsigned *cpu, unsigned *node, void *unused)
+{
+	vdso_read_cpunode(cpu, node);
+
+	return 0;
+}
+
+long getcpu(unsigned *cpu, unsigned *node, void *tcache)
+	__attribute__((weak, alias("__vdso_getcpu")));